This invention relates to a seal, and more particularly, to a seal for a linkage which is subjected to oscillatory motion under widely varying conditions.
In U.S. Pat. No. 3,841,718 (assigned to the Assignee of this invention), a highly effective seal for a track link joint is disclosed. As shown therein, the seal includes a crescent seal ring and an outwardly positioned load ring associated therewith. While the operating characteristics of such a seal have been found to be highly satisfactory, it will be seen that the crescent-shaped seal ring is asymmetrical relative to the mid-circumferential plane of such seal ring. Likewise, the load ring is asymmetrical in relation to the mid-circumferential plane thereof.
While the operating characteristics of a properly positioned load ring and seal ring in accordance with U.S. Pat. No. 3,841,718 have been found to be excellent, it is possible to inadvertently install the entire seal assembly, made up of the seal ring and load ring, backward, and it is also possible to inadvertently install the load ring backward relative to the seal ring. This is so because of the asymmetrical shapes of such load ring and seal ring. In either of these cases, the seal assembly will not provide effective sealing.
Reissue Pat. No. 28,105 discloses a slipper seal in association with a load ring. However, such slipper seal, it will be seen, is not in contact with axially facing end walls. U.S. Pat. No. 3,027,909 and U.S. Pat. No. 3,848,880 disclose seal assemblies wherein no load ring is utilized. This is also the case with U.S. Pat. No. 3,713,660.
U.S. Pat. No. 3,869,132 discloses a sealing ring associated with an inwardly disposed metallic C-ring, with no disclosure of a load ring disposed outwardly of the sealing ring.